METHODLOGY CORE Abstract The initiatives of Healthy People 2020 place a high priority on research and federal policy to eliminate racial and ethnic disparities in health status, health behaviors, functional limitations, and healthcare use. Yet, American Indians (AI), Alaska Natives (AN), and Native Hawaiian and Pacific Islanders (NHPI) suffer a disproportionate burden of hypertension, its attendant CVD and stroke risk factors, as well as clinical CVD and stroke, compared to other US populations. The Native-Controlling Hypertension And Risks through Technology (Native-CHART) Methodology Core is devoted to optimizing blood pressure intervention research with partners that serve these populations. Its goals are to make efficient use of study resources, to optimize internal and external study validity, and to improve inferential ability. Core members will be involved in study design, sample selection, measurement, data collection, data management, data analysis, and dissemination of findings. We integrate methods from epidemiology, biostatistics, health economics, health services and policy, and health outcomes research, augmented with exceptional experience in qualitative methods. Our Specific Aims are to: 1) collaborate with our community partners and the Consortium Core to develop and implement methods for collecting data for the baseline and subsequent needs assessments; 2) apply state-of-the-art research designs, sampling strategies, and analysis techniques to test the impact of novel interventions for the reduction of blood pressure and its attendant CVD and stroke risk factors among AI, AN, and NHPI people with hypertension. This includes locating each Intervention Project within a theoretical framework that reflects the interdependent nature of multilevel interventions; ensuring the reliability and validity of measures, with attention to minimizing measurement error and best practices for data collection; and applying a flexible and comprehensive data analysis strategy guided by multilevel models. This strategy encompasses longitudinal data structures including within-person change, group-randomized trials, and cross-level intervention effects, using random effects estimation, generalized estimating equations, and others; maximizing efficient use of resources in developing policies and procedures; manualizing operations; designing questionnaires and data collection; managing data and statistical analyses; disseminating findings; and integrating qualitative and quantitative methods to contextualize and enhance the cultural relevance and public health impact of the Projects; and 3) perform systematic economic evaluations of the hypertension-control programs through cost-benefit and cost- effectiveness analyses. Our long history of collaboration with the Intervention Project Leaders and Satellite Center Directors is complemented by the Methodology Core?s understanding of the unique needs and challenges inherent in conducting research with AIs, ANs, and NHPIs. The Core will be invaluable in ensuring that Native CHART?s work contributes to better management of hypertension and its attendant risks in these populations.